Messages in this thread | | | Date | Sat, 03 Feb 2007 15:34:57 -1000 | From | akuster <> | Subject | Re: [patch 1/1] PM: Adds remount fs ro at suspend |
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Christoph Hellwig wrote: > On Fri, Feb 02, 2007 at 01:50:10PM -1000, akuster@mvista.com wrote: >> >> This adds the ability for the file system to remounted as read only during a >> system suspend. Log the mount points so when the resume occurs, they can be >> remounted back to their original states. This is so in an advent of a power >> failure, we try our best to keep data from being corrupted or lost. > > Can you please explain why this can't be done in userspace?
I am sure it can. The idea came from customer inputs, speed is my guess. echo mem > /sys/../state seems a whole lot simpler and cleaner than having userspace figure out what it mounted and then doing echo mem.
In fact > all existing suspend solutions seem to be doing fine doing things like > this in userspace.
I guess I missed that boat. If you don't mind, could you point at one solution.
> >> +static struct suspremount *suspremount_list; >> + < snipped>
>> +void suspend_remount_all_fs_ro(void) >> +{ >> + suspremount_list = NULL; >> + emergency_remount(); > > NACK. emergency_remount is exactly what it sais and should never ever > be used for a system that you want to keep on using later on.
The code "emergency_remount" is almost identical to what we have been using. I wanted to reuse existing code rather than dup it.
If you > look at it's implementation it's not correct and can't serve as more than > a bandaid for susrq.
From our customer experience, we have not gotten an bad feedback on it. It seems to address there needs.
In fact we should probably just remove it.. > >> +EXPORT_SYMBOL(suspend_remount_all_fs_ro); > > And something like this for sure should not be exported. > >> +EXPORT_SYMBOL(resume_remount_fs_rw); > > ditto. >
All the code corrects have been address in my upcoming version.
Many thanks for you time and feedback.
Armin - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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